The invention relates to cards that have electronics micro-circuits and that are more generally known as xe2x80x9csmart cardsxe2x80x9d or xe2x80x9cchip cardsxe2x80x9d.
One of the problems that is frequently encountered for mass consumer products is the problem of standardization, so that products coming from different manufacturers can be used in the same equipment.
This applies particularly to smart cards: they are used, for example, in public telephones, in card readers associated with personal computers, and in banking applications, etc. It has thus been necessary to adopt precise construction standards that all of the manufacturers must comply with. The general public is now very well acquainted with the format that has been adopted, at least as regards the outside dimensions of the card: it is the format of conventional credit cards with magnetic stripes. The smart card is a rectangle that is about 8.5 cm long by 5.4 cm wide, and that is a little less than one millimeter thick (international Standards ISO 7810 and 7816 today).
As a result, naturally, the machines for manufacturing smart cards are built as a function of those standards, so as to be capable of producing cards that comply with the standards.
But in certain applications, it has become apparent that that format is not ideal. This applies in particular for miniaturized applications. For example, when a smart card is to be used in a handheld housing of very small size, the current format, despite its small size, is not necessarily acceptable. By way of example, mention might be made of the mobile radiotelephone or xe2x80x9ccellphonexe2x80x9d whose handheld housing needs to use smart cards of format much smaller than the current format and complying with the GSM 11-11 Standard.
An object of the invention is to provide an inexpensive technical solution for making smart cards of format smaller than the generally-used format.
Methods have already been proposed in the prior art for making smart cards of small format. A method, described in particular in Patent EP-0 521 778, consists in performing all of the steps of manufacturing a smart card of standard format, and in performing an additional step of partially pre-cutting the standard-format card so that a small-format card can be detached from it merely by pressing with the fingers. The partial pre-cutting is performed around a micromodule contained in the card. The pre-cut is constituted by a slot extending around the outline of the small-format card, the slot being interrupted locally to leave webs between the small-format card and the standard-format card. In particular, those webs are of reduced thickness in the vicinity of the small-format card so as to enable it to be separated from the remainder of the body of the standard-format card merely by pushing it out with the fingers.
A major drawback of that type of method lies in the fact that the small-format card can, under certain rare conditions, not be detached very cleanly. The shear forces can be insufficiently concentrated on the location at which the detaching should take place, so that the small-format card can have uneven edges. In addition, during bending testing over the width of the standard-format card, the webs can be twisted and can be subjected to stresses. Exceptionally, such stresses can damage the micromodule contained in the card or can break one of the webs or xe2x80x9cstrapsxe2x80x9d unintentionally. In which case, the large-format card might not comply with Standard ISO 7816 as regards its bending and twisting strength.
The invention makes it possible to solve the above-mentioned problems by proposing an improved card. To this end, it provides a large-format smart card comprising a card body and a mini-card which is connected thereto by at least one strap, said strap including at least one portion disposed in the vicinity of the mini-card and shaped to constitute a place at which breaking is forced to occur or a xe2x80x9cscore linexe2x80x9d in order to enable the mini-card to be separated by pushing it out with a finger, said smart card being characterized in that said strap also includes a second portion disposed in the vicinity of the card body and suitable for forming a hinge.
According to another characteristic of the invention, the hinge is constituted by a thinned neck formed by thinning the thickness of the strap.
According to yet another characteristic of the invention, the thinned neck is in the form of a trough having a rounded profile.
According to yet another characteristic of the invention, the score line is formed by two scores respectively on the front and on the back of the card.
According to yet another characteristic of the invention, the strap(s) is/are provided with connection fillets for connecting respectively to the card and to the mini-card.
According to another characteristic of the invention, the length of the strap on the side closer to the mini-card is shorter than the length of the strap on the side closer to the card body.
According to yet another characteristic, the smart card further comprises a long strap along a short side of the mini-card, which long strap includes a score line formed by two scores that extend over its entire length and on respective ones of both the front and the back of the card.
By subdividing the strap into two separate portions respectively comprising a thinned neck and a score line, the mechanical stresses are also separated. By means of the invention, the mini-card is easier to detach, and can be detached cleanly both on the front and on the back of the card. In addition, the mini-card offers good resistance to deformation due to bending testing of the card.
Another object of the invention is to provide a method of making a small-format smart card, comprising the entire method of manufacturing a standard-format smart card, and an additional step of forming a partial cut-out to the dimensions of the mini-card, said partial cut-out being constituted by a slot interrupted locally by at least one strap between the small-format card and the standard-format card, characterized in that the strap(s) is/are made so that it/each of them includes a first portion disposed in the vicinity of the mini-card and shaped to constitute a score line, and a second portion disposed in the vicinity of the standard-format card and constituted by a thinned neck formed by thinning the thickness of the strap, said first and second portions being implemented over the entire length of the strap and over both the front and the back of the card.
The partial cut-out makes it possible in particular to detach a card of predetermined small size from the card of standardized size.
The small card is detached only after the end of all of the manufacturing, testing, and customization printing operations, so that any standard manufacturing and testing equipment can be used without having to satisfy any constraint due to the small size desired for the final card.
Therefore, the manufacturing cost is low because it is not necessary to invest in costly additional manufacturing equipment merely to overcome the size problems.